Project N9 / N10 3d Printed bodyshell

[Paul_sterling]

Hi Folks, 

As mentioned on the J21 thread I'm working on an N9 as well, though this could be deviated to an N10, depending on chassis choice. 

 

 

This all began with the purchase of a ready built N9 nu-cast, which I think I can  do a better job of with printing. The Wainwright C-class is another suitable donor, for the N9, whereas I'm considering the Jinty for an N10.

 

The N9 is, by and large, the same as the J21 up the the front of the cab. Some features move a little, but changing the position of the CAD planes brings this in line. 

 

20210526-1 by Paul Sterling, on Flickr

This shows the initial modifications of a J21 CAD file. 

 

 

 

 

 

I plan on producing a similar rear truck arrangement to the 56XX, but I'm undecided about whether to include a rotating cylinder, or just utilise sideway play, as I was advised within the LH&JC No.5 thread that the cylinder could be glued solid if it begins to cause trouble due to wear. 

 

Unlike the J21, I'm not going to produce a number of variants, the Westinghouse pump, vac pipe, side feed, and lubricator can all be cut off if people don't want that particular feature on a variant.

 

Thanks, Paul. 

[Paul_sterling]

So yesterday I set away a print, two locos, the N9 and N10, to do a fit trial.

 

IMG_20210616_093939 by Paul Sterling, on Flickr

 

I stopped the print this morning so I could check it over before work. I don't need a chimney for a fit trial, and the models were likely to need minor (or major) changes anyway.

 

IMG_20210616_093949 by Paul Sterling, on Flickr

 

As it was, both printed rather well (these pics above are of the N10 only)

 

IMG_20210616_093956 by Paul Sterling, on Flickr

 

The side valances are slightly deeper than the J21's, and I had failed to factor in for that with the sacrificial frame (which was referenced from the top surface of the running plate), so they were tough to get off, resulting in taking a lump of the valance with it. This was easy to amend. 

 

IMG_20210616_094007 by Paul Sterling, on Flickr

 

The N9 is more straightforward, as it used all of the chassis interfaces and pockets established with the J21, only the rear has changed underneath. 

 

IMG_20210616_094025 by Paul Sterling, on Flickr

 

The trialled buffer shanks came out quite well, I want to add 0.1mm onto the diameter for a little extra strength, but otherwise I just need to see how the Markits buffers fit. Having these shanks on the model gives me a new surface to create buffer-beam supports off, so there are less supports that have to be cut off the beam itself, and the inboard pockets have been carried on up to the running plate, thus creating some decent supporting surfaces close to the outside edge of the buffers, often an area that needs as much strength as it can, as its thin and highly loaded. 

Thanks, Paul.